1. Field of the Invention
The present invention relates to a voltage detection connector for a fuel cell, and to a fuel cell adapted for same.
2. Description of the Related Art
A fuel cell used in electric vehicles and hybrid vehicles, for example, is formed by the stacking multiple electrical generation units known as cells. Each cell has an electrolyte membrane, made of an ion exchange membrane that is sandwiched between an anode and a cathode and further sandwiched outside by a pair of separators. The separators have passages for supplying fuel gas, such as hydrogen gas and the like, and an oxidant gas, such as air, to the anode and to the cathode. By supplying fuel gas and oxidant gas via these passages, a chemical reaction occurs within the cell, and electricity is generated.
In such fuel cells, it is necessary to manage the electrical generation condition of each of the cells to control the supply of fuel gas and oxidant gas, and to detect bad cells. The method of doing this is detecting the voltage generated by each cell (hereinafter “cell voltage”) and controlling in response to the cell voltage. A connector 100, having a connector case 10, as shown in FIG. 11, is usually used. Connector 100 houses detection terminals (not illustrated) arranged in a row at a spacing that is equal to the spacing of the separators of the plurality of cells. A mating part 12 for locking is provided at the top part of the connector 100. As shown in FIG. 12, the connector 100 is mounted to the fuel cell 102. The detection terminals for detecting the voltage make contact with each of the separators 16 of each cell 14, and electrical leads 18 from each of the detection terminals are used to measure the voltage between the separators 16 to measure the cell voltages. The fuel cell 102 is provided with a mating part 20, made of resin, to which the connector 100 is attached. This mating part 20 mates together with the mating part 12 of the connector 100, thereby fixing the connector 100 to the fuel cell 102. In FIG. 12, in order to clearly show the condition of the attached connector, part of the fuel cell 102 is cut away.
Japanese Patent Application Publication No. JP-A-2002-313399, for example, describes a detection terminal made of a resilient material. The terminal is fixed to a base member that has a mating part mating with a separator, and a linking means for connecting to detection terminals of neighboring cells. Japanese Patent Application Publication No. JP-A-2004-127776 describes a connector for voltage detection, in which a connector and a circuit board are combined within a case.
In the foregoing related art, with attaching the connector 100, it is difficult to view the position of the detection terminals provided thereon. For this reason, proper insertion of the electrodes of the fuel cell into the detection terminal might not be possible, and offset of the attachment position of the connector 100 or other attachment problems can occur.
In recent years, with improvements in the electrical generation efficiency of the cells making up fuel cells, the thickness of each cell has decreased. When cells become thin, in the case of the connector 100 shown in FIG. 11, as shown in FIG. 13 as viewed in the direction of the arrow I shown in FIG. 12, there is an interfering portion (shown as the hatched area in FIG. 13) in which there is mutual interference between the connector cases 10 of neighboring connectors 100 that are attached. This interference could hinder connection of the connectors 100. If the thickness of the walls of the connector case 10 is made thin, so as to avoid the interference, the strength of the connector 100 becomes insufficient. This could result in problems such as a reduction in the manufacturing yield of the connector 100, and in damage when attaching the connector 100.